var score = [59, 66, 64, 80, 78, 90, 55, 37, 60, 52];
var failScore = [];
for (var i = 0; i < score.length; i++) {
    if (score[i] < 60) {
        failScore.push(score[i]);
    }
}
console.log(failScore);
console.log('不及格的人数为:' + failScore.length);